Structure for Shaping and Applying a Propagating Shock Wave to an Area of an Explosive Load to Increase an Energetic Shock Impact Effect on a Target

ABSTRACT

Various embodiments including an improved shaped demolition charge apparatus and methods associated with the invention are provided in a cylindrical dynamic access structure (“CDAS”), which can include a wave shaper, a main charge, and a booster disk. An exemplary embodiment comprises a waver shaper, and a main charge, which can be plastic, bonded explosive. A wave shaper can comprise of two-layered structure in which a void is formed. A wave shaper can be disposed between a booster disk and a main charge such that the booster disk is only in contact with the main charge along an outer edge of the booster disk. A wave shaper directs or channels a shock wave from the booster disk to an outer portion of the main charge. A container can be formed or adapted around a cover, booster disk, main charge, and wave shaper.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

The invention described herein includes contributions by one or moreemployees of the Department of the Navy made in performance of officialduties and may be manufactured, used and licensed by or for the UnitedStates Government for any governmental purpose without payment of anyroyalties thereon. This invention (Navy Case 101,477) is assigned to theUnited States Government and is available for licensing for commercialpurposes. Licensing and technical inquiries may be directed to theTechnology Transfer Office, Naval Surface Warfare Center Crane, email:Cran_CTO@navy.mil.

BACKGROUND AND SUMMARY OF THE INVENTION

Aspects disclosed herein relate to the field of explosive devices. Inparticular, one embodiment can include a cylindrical dynamic accessstructure with a plastic bonded explosive material.

Typical bulk explosive charge includes generic containers or othersimple configurations consisting primarily of packaged or hand packedexplosive, e.g., C4 or TNT. The performance of these devices isinefficient both in how they are initiated and how the shock waveprogresses through the explosive in such a device. Therefore, moreexplosive materials are required by these devices than would otherwisebe necessary with a more optimal design. Furthermore, some of these bulkexplosive designs have safety issues that can be improved.

An apparatus in accordance with an embodiment of the invention providesa demolition charge with enhanced capabilities beyond those oftraditional bulk charges. A cylindrical dynamic access structure(“CDAS”) with plastic bonded explosive combines an optimized shock waveof the CDAS design with a high performance precision explosive. A chargethat combines a CDAS design and plastic bonded explosive according to anembodiment of the invention can perform, for example, twenty percent tothirty percent more effectively than traditional C4 bulk charges.

One advantage of an exemplary embodiment is an ability to produceincreased output from a charge mass than a bulk charge could producewith a similar charge mass and a detonator without an embodiment of theinvention. Additionally, increased effectiveness of an exemplaryembodiment allows a bulk charge having less mass than bulk chargeswithout an embodiment of the invention.

Another advantage of an embodiment of the invention is an ability toproduce a more energetic shock impact on the target than provided bytraditional bulk charges. Traditionally charges have less optimal shockfront impacts in the form of point contact or shock fronts directedparallel to the charge. For example, an exemplary embodiment provides animpact that is cylindrical. This cylindrical loading has at least twoadvantages. First, the cylindrical loading provided by the CDAS resultsin an intense load applied simultaneously over a greater area. Second,cylindrical loading provided by the exemplary CDAS results in furtheramplification of energy in a form of colliding shocks developed as ashock wave expands towards the center of the cylinder.

In one embodiment, a combination of the CDAS design and plastic bondedexplosive load amplifies the effectiveness of the hardware design.Plastic bonded explosive is more energetic than hand loaded explosivessuch as, for example, C4. Also, a production loaded explosive, e.g.,plastic bonded explosive, is more uniform and more dense, which providesa more uniform and energetic detonation.

An apparatus in accordance with an embodiment of the invention providesadditional advantages as well. Such an apparatus, for example, providesthe user with a factory loaded charge, thus eliminating the need tohand-build traditional demolition charges. This saves the user time andimproves safety by reducing direct exposure to explosive chemicals andthe risks associated with hand-forming energetic materials. Also, theCDAS can incorporate a priming or detonator well placed through a cover,e.g., a center of the cover, of the CDAS outer shell allowing for easyinstallation and removal of detonators or primers with various diameterswithout the need for additional adapters for a detonator or primer andalso providing for quick installation or removal of the detonator orprimer.

Additional features and advantages of the present invention will becomeapparent to those skilled in the art upon consideration of the followingdetailed description of the illustrative embodiment exemplifying thebest mode of carrying out the invention as presently perceived.

BRIEF DESCRIPTION OF THE DRAWINGS

The detailed description of the drawings particularly refers to theaccompanying figures in which:

FIG. 1 shows a perspective external view of an exemplary embodiment ofthe invention;

FIG. 2 shows a cross-sectional view of an exemplary embodiment;

FIG. 3 shows an exploded view of an exemplary embodiment; and

FIG. 4 shows a block diagram illustrating one method of manufacturing anexemplary embodiment.

DETAILED DESCRIPTION OF THE DRAWINGS

The embodiments of the invention described herein are not intended to beexhaustive or to limit the invention to precise forms disclosed. Rather,the embodiments selected for description have been chosen to enable oneskilled in the art to practice the invention.

Referring initially to FIG. 1, a CDAS with plastic bonded explosives isshown generally at 10. Embodiments comprise a base plate 12, whichsupports a container 14, and a main charge 24 (not shown). In certainembodiments a container 14 can have a plurality of containers stacked ontop of each other to form varying heights. One embodiment can include,for example, a polycarbonate container 14. A container 14 can surround amain charge 24 (not shown). A container 14 can support a cover 16. Aprimer well 18 can be disposed on the center of cover 16. A primer well18 can support an adapter 28, which can receive various types ofdetonators, such as, for example, safety fuse, shock tube detonator,electrical detonators, electronic detonators, or the like. An exemplarydiameter of the CDAS can be, e.g., 12 inches across, e.g., at the topplate 16, at the base plate 12, or at some height of the CDAS. Height ofthe exemplary CDAS, e.g., from the base plate 12 to the top plate 16,can be, e.g., 7 inches. Weight of this embodiment can be, e.g., 40pounds. A charge design is not limited to a fixed diameter, height, orweight and can be scaled for various applications. The exemplaryembodiment shown in FIG. 1 can be placed on a target structure, e.g., byhand, with the base plate 12 substantially adjacent to the targetstructure.

Referring to FIG. 2, a cross-sectional view of an exemplary embodimentis shown. One exemplary embodiment of the invention includes a maincharge 24 which can be formed adjacent to an entire inner surface ofbase plate 12 and container 14. A main charge 24 can comprise a plasticbonded explosive, e.g., PBXN-110. PBXN-110 is a factory-loaded,precision-loaded explosive. A PBXN-110 main charge composition can becomprised of, e.g., 86 to 88 percent HMX, and 12 to 14 percent binder byweight. The exemplary embodiment of the main charge can comprise ofexplosives other than PBXN-110, or in any explosive combination withPBXN-110. A booster disk 30 in the embodiment shown in FIG. 2 comprisesa disk of explosive booster material positioned at the top of the maincharge 24 and the wave shaper 20. One side of booster disk 30 ispositioned adjacent to top plate 16, while the other side of boosterdisk 30 is positioned adjacent to wave shaper 20 and main charge 24. Thewave shaper 20 prevents contact between booster disk 30 and main charge24 except for a ring that contacts the outer diameter of booster disk30. In embodiments the wave shaper 20 separates the shock from thebooster 30 from the main charge 24 and manipulates or shapes the shockwave from the booster hits or initiates the main charge 24. In certainembodiments a wave shaper 20 can have a first piece and a second piece,which can be connected to form a void 32. A wave shaper 20 can compriseone or more pieces. In the exemplary embodiment the wave shaper 20 canbe plastic. In certain embodiments the waver shaper 20 can be steel,aluminum, brass, PTFE, or the like. A void 32 can be formed by andenclosed within the wave shaper 20 as shown in FIG. 2. In certainembodiments the void 32 can be air, gases, or the like. In exemplaryembodiments the wave shaper 20 forms the air void 32 within the CDAS.The wave shaper 20 is not limited to a cylindrical shape, it can be anyshape that achieves effects in accordance with embodiments of theinvention for example, rectangular, spherical, and the like.

The exemplary embodiment shown in FIG. 2 does not comprise a means ofinitiation and requires a user-installed blasting cap or similardetonator. Embodiments disclosed herein include a flexible charge primer26, which allows for high velocity, high-energy detonations. Inembodiments a flexible charge primer 26 has a center hole for adetonator to be placed in contact with a booster 30. A flexible chargeprimer 26 can comprise of, e.g., Detaprime. Detaprime is a compact,high-detonation pressure primer. Alternative embodiments can comprise apre-installed means of initiation. In an exemplary embodiment, uponinitiation of a user-installed detonator, the booster disk detonates inan expanding circular shock wave across the top of the CDAS, between atop plate 16 and a wave shaper 20. When this expanding circular shockwave reaches the edge of booster disk 30, it contacts and detonates amain charge 24. This detonation of the main charge 24 occurssubstantially simultaneously in a ring around the booster disk 30, wherethe booster disk 30 is in contact with main charge 24. This simultaneousring of detonation at the top portion of main charge 24 results in acylindrical shaped shock front progressing through the main chargetoward the base plate 12. This exemplary cylindrical shock patternproduces an intense load applied simultaneously over a great area andinvolves amplification of the energy in the form of colliding shocksdeveloped as the shock wave expands towards the center of the CDAS.

Referring to FIG. 3, an exploded diagram view of an exemplary embodimentis shown. This view shows a detonator adapter 28, a flexible chargeprimer 26 (not shown), a primer well 18, a top plate 16, a booster disk30, a wave shaper 20, and a main charge 24, in order from top to bottom,exploded out of a container 14 and away from base plate 12. The waveshaper 20 fits down into the depression in the top of main charge 24 andbooster disk 30 fits onto the top of wave shaper 20 and main charge 24such that booster disk 30 is in contact with main charge 24 along theouter edge of booster disk 30, with wave shaper 20 preventing most ofthe bottom of booster disk 30 from being in contact with main charge 24.When the components of this embodiment are collapsed back into position,top plate 16 seals to a container 14 to enclose (from top to bottom)booster disk 30, wave shaper 20, and the main charge 24 within the CDAScomprised of top plate 16, container 14, base plate 12, primer well 18,and adaptor 28.

Referring to FIG. 4, a block diagram illustrating an exemplary methodassociated with manufacturing an exemplary CDAS. As a preliminary stepto one variant of the exemplary method, an exemplary process can includeproviding CDAS components such as described herein. At step 50,providing a container and disposing a main charge therein wherein themain charge has a recess formed by a cavity so as to form walls of themain charge surrounding the cavity. At step 52, forming a wave shapersubstantially in a shape of the cavity and disposing the wave shaperwithin the main charge cavity so it is surrounded and flush with themain charge's cavity walls. At step 54, placing a booster disk above thewave shaper and main charge within the container so that the boosterdisk is in contact with the wave shaper and main charge's cavity walls.At step 56, attaching a cover with a detonator well to the containerabove the booster disk. At step 58, providing and insert a detonatorinto the detonator well. At step 60, coupling a base to a side of thecontainer opposing the cover.

Note that an exemplary embodiment can omit step 58 until a time the CDASis ready for use. An exemplary wave shaper can be formed by either, forexample, one piece or multiple pieces thereby forming a void inside thewave shaper which can have for example, air, gas, or the like within it.An exemplary main charge can be adapted so that it can be inserted intothe container, leaving an open area for a wave shaper and an enclosedarea between the inner wall of the container, and the outer wall of thewave shaper, which allows the outer area of the main charge to be incontact with a booster disk. An exemplary main charge can be placed sothat it is adjacent to and touches the outer area of a booster disk,surrounds the waver shaper, and also in lateral contact with an innerwall of a container. An exemplary base can be placed adjacent to a maincharge and connected to a container.

Although the invention has been described in detail with reference tocertain preferred embodiments, variations and modifications exist withinthe spirit and scope of the invention as described and defined in thefollowing claims.

1. An explosive device comprising: a detonator; a primer; a covercomprising a priming well at a center section of said cover adapted toremovably receive said detonator, and said primer; a booster diskadapted to generate a first shock wave based on firing said detonator; amain charge adapted to generate an explosive force based on said firstshock wave; a wave shaper structure comprising a first and second layerstructure operable for channeling said first shock wave, said waveshaper is disposed between said booster disk and said main charge,wherein said wave shaper structure is operable to direct or channel saidfirst shock wave from the booster disk to an outer portion of said maincharge; and a container formed or adapted for enclosing or coupling withsaid cover, said booster disk, said wave shaper, and said main charge.2. An explosive device as set forth in claim 1, wherein said main chargecomprises a plastic bonded explosive.
 3. An explosive device as setforth in claim 1, wherein said booster disk comprises a boosterexplosive.
 4. An explosive device as set forth in claim 1, wherein saidcover removably receives a detonator or initiator at a first location ina center section.
 5. An explosive device as set forth in claim 1,wherein said priming well is formed to accept a flexible charge primer.6. An explosive device as set forth in claim 2, wherein said plasticbonded explosive comprises PBXN-110.
 7. An explosive device as set forthin claim 1, wherein said container comprises a polycarbonate material.8. An explosive device as set forth in claim 1, wherein said containeris 6 to 18 inches in diameter and 5 to 20 inches in height.
 9. Anexplosive device as set forth in claim 1, wherein said first shock wavesimultaneously or near simultaneously detonates said main charge at saidouter portion of said main charge.
 10. An explosive device comprising acharge and a means operable for enabling detonation of a booster diskthat results in the subsequent detonation of the charge simultaneouslyalong a ring at an outer edge of said booster disk.
 11. A method formaking an explosive device comprising the steps of: placing a primerinto a center portion of a priming well, wherein said priming well isadapted to removably receive a detonator; aligning and connecting saidpriming well at a center section of a cover; connecting a container tosaid cover, wherein said container can be a plurality of containersplaced on each other; placing a booster disk adjacent to said primingwell and said cover; forming a wave shaper, wherein said wave shapercomprises a first and second structure wherein a void is formed; placingsaid wave shaper adjacent to said booster disk; adapting a main chargewherein said main charge is placed within the container adjacent to saidbooster disk, and disposed around said wave shaper; and connecting abase to said container and adjacent to said main charge.
 12. A method ofmanufacturing an improved explosive comprising providing a container anddisposing a main charge therein wherein the main charge has a recessformed by a cavity so as to form walls of the main charge surroundingthe cavity; providing an explosive booster disk operable to generate afirst shock wave operable to detonate said main charge; forming a shockwave shaper substantially in a shape of the cavity and formed with anair gap within said shock wave shaper, said shock wave shaper formed tochannel said first shock wave along a surface of said wave shapertowards said walls of the main charge surrounding the cavity; disposingthe wave shaper within the main charge cavity so it is surrounded andflush with the main charge's cavity walls; placing said booster diskabove the wave shaper and main charge within the container so that thebooster disk is in contact with the wave shaper and main charge's cavitywalls; attaching a cover with a detonator well to the container abovethe booster disk; and coupling a base to a side of the containeropposing the cover.
 13. A method as in claim 12, further comprisingproviding and inserting a detonator into the detonator well.
 14. Amethod of manufacturing an explosive device comprising: providing adetonator; providing a primer; providing a cover comprising a primingwell at a center section of said cover adapted to removably receive saiddetonator, and said primer; providing a booster disk adapted to generatea first shock wave based on firing said detonator; providing a maincharge adapted to generate an explosive force based on said first shockwave; providing a wave shaper structure comprising a first and secondlayer structure operable for channeling said first shock wave, said waveshaper is disposed between said booster disk and said main charge,wherein said wave shaper structure is operable to direct or channel saidfirst shock wave from the booster disk to an outer portion of said maincharge; and providing a container formed or adapted for enclosing orcoupling with said cover, said booster disk, said wave shaper, and saidmain charge.
 15. A method as set forth in claim 14, wherein said maincharge comprises a plastic bonded explosive.
 16. A method as set forthin claim 14, wherein said booster disk comprises a booster explosive.17. A method as set forth in claim 14, wherein said cover removablyreceives a detonator or initiator at a first location in a centersection.
 18. A method as set forth in claim 14, wherein said primingwell is formed to accept a flexible charge primer.
 19. A method as setforth in claim 15, wherein said plastic bonded explosive comprisesPBXN-110.
 20. A method as set forth in claim 14, wherein said containercomprises a polycarbonate material.
 21. A method as set forth in claim14, wherein said first shock wave simultaneously or near simultaneouslydetonates said main charge at said outer portion of said main charge.22. An explosive device comprising a container and an explosive meansoperable for channeling of a booster disk detonation shock wave so as todetonate a main charge within the explosive means simultaneously along aring or an outer edge of said booster disk in contact or proximity toouter sections of the main charge so as to result in reflection ordirection of detonation of the main charge from an outer ring area ofthe main charge inwards towards a center of the main charge.